昷 is the source form behind 温 (warm) and is not used independently in modern Chinese. It pictures a vessel offered to a prisoner, an act of kindness, and gives the sound in 温 (warm), 瘟 (plague), 愠 (sullen / annoyed), and 蕴 (to hold within).
register
Archaic. One old reading also files 昷 under a 'clear-headed' sense; the 'warm / kind' sense is the one that explains its large phonetic family.